Smoking agent microcapsule and heating cigarette

Abstract

The invention relates to the field of tobacco, and discloses a smoke agent microcapsule and a heated cigarette. The smoke agent microcapsule comprises a core material and a wall material, the core material contains a smoke agent and a phase change material, the phase change material is a crystal, and the wall material contains organosilicon modified polyurethane. The preparation method comprises the following steps: (1) in the presence of an initiator, carrying out mixed reaction I on a double-bond-terminated silicon-containing polyurethane prepolymer, acrylate and a smoke agent to obtain an oil phase; dissolving a surfactant in water to obtain a water phase; and (2) mixing the oil phase and the water phase, emulsifying to obtain an emulsion, carrying out a mixed reaction II on the emulsion, and demulsifying. The smoking agent microcapsule is high in stability at normal temperature, the wall breaking rate of the smoking agent microcapsule under the high-temperature heating condition can be increased, and then the smoking effect and the user experience are improved.

Description

Technical Field

[0001] The present invention relates to the field of tobacco, and in particular to a smoking agent microcapsule and a heated cigarette. Background Art

[0002] In recent years, with the increasingly stringent tobacco control situation and growing consumer awareness of health, new tobacco products have become increasingly popular. Aerosol-generating products such as heated cigarettes have undergone rapid development and optimization in recent years, initially achieving a superior smoking experience. Due to the unique heating method used in heated cigarettes, the tobacco material itself cannot release sufficient aerosol, resulting in low smoke volumes. Therefore, atomizers such as glycerin and propylene glycol are often added to supplement the smoke produced by heating. However, glycerin and propylene glycol absorb moisture from the air when exposed to air, increasing the water content of the heated cigarette. This results in excessive moisture content in the smoke from the first two puffs (especially the first puff). This increased heat capacity results in a burning sensation in the mouth when smoking heated cigarettes, resulting in a poor user experience.

[0003] The main solution at present is to use microcapsules with core materials of liquid aerosols such as glycerin and propylene glycol to reduce their hygroscopicity. However, it has been found in practice that in order to ensure that liquid aerosols such as glycerin and propylene glycol can be stably stored in microcapsules, the wall material of the microcapsules is often relatively thick, which makes it more difficult to break the wall by heating. Through experiments, it was found that at the end of the regular puffing time, a large number of microcapsules were still not broken by heating.

[0004] Therefore, there is an urgent need to provide a smoke-generating agent microcapsule that can have a high wall-breaking rate under high-temperature heating conditions to improve user experience. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems of low wall-breaking rate and poor user experience of smoke-generating agent microcapsules in the prior art, and to provide a smoke-generating agent microcapsule and a heated cigarette. The smoke-generating agent microcapsule has high stability at room temperature and can improve its wall-breaking rate under high-temperature heating conditions, thereby improving the smoking effect and user experience.

[0006] A first aspect of the present invention provides a smoke-generating agent microcapsule. The smoke-generating agent microcapsule comprises a core material and a wall material. The core material contains a smoke-generating agent and a phase change material. The phase change material is a crystal.

[0007] Preferably, the peak temperature of the heating curve of the smoke agent microcapsule is T pm The melting point temperature T of the core material m The absolute value of the temperature difference |T pm -T m |≤12.0℃; further preferably, |T pm -T m|≤9.8℃; More preferably, |T pm -T m |≤7.8℃; especially preferably, |T pm -T m |≤4.8℃; More preferably, |T pm -T m ∣≤2.8℃.

[0008] Preferably, |T pm -T m |≤1.8℃; further preferably, |T pm -T m |≤0.9℃; More preferably, |T pm -T m |≤0.5℃; particularly preferably, |T pm -T m ∣≤0.2℃.

[0009] Preferably, the mass ratio of the core material to the wall material in the smoke generating agent microcapsules is 1.6-3.8:1.

[0010] Preferably, the coverage rate of the smoke-generating agent microcapsules is 65-90%.

[0011] Preferably, the melting point of the phase change material is ≥90°C.

[0012] Preferably, the melting enthalpy ΔH of the phase change material m ≥130 J·g -1 ; Further preferably, ΔH m ≥160 J·g -1 ; Further preferably, ΔH m ≥180 J·g -1 ; Particularly preferably, ΔH m ≥210 J·g -1 .

[0013] Preferably, ΔH m ≥230 J·g -1 ; Further preferably, ΔH m ≥260 J·g -1 ; Further preferably, ΔH m ≥280 J·g -1 ; Particularly preferably, ΔH m ≥310 J·g -1 .

[0014] Preferably, the smoke generating agent is selected from at least one of propylene glycol, ethylene glycol, glycerin, vanillin, vanillic acid, vanillyl acrylate, styrene, benzaldehyde, phenylpropanol, acetophenone, nicotine, nicotinic acid and amino acids, and more preferably glycerin.

[0015] Preferably, the mass ratio of the smoke generating agent to the phase change material is 1:0.25-4.

[0016] Preferably, the phase change material comprises sugar alcohol, and the sugar alcohol is selected from at least one of sorbitol, mannitol, erythritol, maltitol, lactitol and xylitol.

[0017] Preferably, the phase change material comprises a phase change material having a lower first melting point temperature T m1 The first sugar alcohol and the second sugar alcohol having a higher melting point temperature T m2 The second sugar alcohol, the peak temperature of the heating curve of the smoke-generating agent microcapsule T pm With T m1 、T m2 The relationship is T pm ∈[T m1 ,T m2 ].

[0018] Preferably, the wall material contains organosilicon-modified polyurethane, which is obtained by polymerization of silicon-containing polyurethane prepolymer and polyacrylate.

[0019] Preferably, the polyacrylate is at least one selected from polyethyl methacrylate, polyethyl methacrylate derivatives, polymethyl methacrylate and polymethyl methacrylate derivatives.

[0020] Preferably, the weight average molecular weight of the polyacrylate is 200-10,000.

[0021] Preferably, the polymerization reaction is carried out in the presence of an initiator.

[0022] Preferably, the initiator is selected from at least one of peroxides, sulfur-containing compounds, nitrites and lead compounds.

[0023] Preferably, the silicon-containing polyurethane prepolymer is obtained by mixing silicone, diisocyanate and hydroxyethyl acrylate.

[0024] Preferably, the organosilicon is selected from at least one of dimethyl silicone oil, hydroxy silicone oil, silane, silicone, polysiloxane, long-chain alkyl silicone oil, amino silicone oil and amide silicone oil.

[0025] Preferably, the weight average molecular weight of the organosilicon is 200-10,000.

[0026] Preferably, the diisocyanate is at least one selected from toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate.

[0027] Preferably, the mixing reaction is carried out in the presence of an organotin catalyst and an organic solvent.

[0028] Preferably, the organotin catalyst is at least one selected from dibutyltin dilaurate, dibutyltin diacetate and stannous octoate.

[0029] Preferably, the organic solvent is selected from at least one of tetrahydrofuran, xylene, and n-butyl acetate.

[0030] Preferably, the structure of the silicon-containing polyurethane prepolymer is as shown in formula (I); Formula (I); wherein R1 is selected from C6-10 alkylene and C6-C14 arylene, and n is an integer greater than 3.

[0031] Preferably, the preparation method of the smoke-generating agent microcapsules is at least one selected from the group consisting of spray drying, emulsion polymerization, coacervation, in-situ polymerization and sol-gel methods.

[0032] A second aspect of the present invention provides a heated cigarette, comprising the smoking agent microcapsules described in the first aspect.

[0033] Preferably, the heated cigarette includes a smoke-generating portion and a filter portion, and the smoke-generating agent microcapsules are arranged in the smoke-generating portion.

[0034] Preferably, the mass loss rate of thermal decomposition of the smoke-generating agent microcapsules at a temperature not higher than 350° C. is ≥40%.

[0035] Preferably, the heated cigarette further comprises cigarette paper wrapping the smoking portion, and the smoking agent microcapsules are arranged on the cigarette paper.

[0036] Through the above technical solution, the beneficial effects of the present invention are: The smoke-generating agent microcapsules provided by the present invention include a core material and a wall material. The smoke-generating agent contained in the core material can interact with the phase change material through hydrogen bonds to form a eutectic. The melting peak of the eutectic is relatively single and has a larger specific gravity than that of a conventional liquid smoke-generating agent. After reaching the phase change temperature, the eutectic undergoes phase change, destroying the microcapsule structure and slowly releasing smoke. The high-temperature resistant wall layer will not decompose, making it safer. Through the coordinated action of the core material and the wall material, the stability of the smoke-generating agent microcapsules at room temperature can be improved, and the influence of the drastic temperature change of the tobacco part before and after each puff on the continuous smoking can be avoided, thereby delaying the overall smoking process of the tobacco and improving the sustained-release effect of the smoke. The wall-breaking rate of the smoke-generating agent microcapsules under high-temperature heating conditions can also be improved, so that the smoke-generating agent is released uniformly and stably at high temperature, which can further improve the sustained-release effect of the smoke and reduce the influence of the hygroscopicity of the smoke-generating agent exposed to the outside. The smoke-generating agent has significant market prospects.

[0037] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a reaction principle diagram of preparing a silicon-containing polyurethane prepolymer in Preparation Example 1 of the present invention; Figure 2 This is an electron microscope image of the smoke agent microcapsules prepared in Example 1 of the present invention; Figure 3 This is an electron microscope image of the smoke agent microcapsules prepared in Example 4 of the present invention; Figure 4 This is an electron microscope image of the smoke agent microcapsules prepared in Example 5 of the present invention; Figure 5 This is an electron microscope image of the smoke agent microcapsules prepared in Example 6 of the present invention; Figure 6 This is an electron microscope image of the smoke agent microcapsules prepared in Example 7 of the present invention; Figure 7 This is an electron microscope image of the smoke agent microcapsules prepared in Example 8 of the present invention; Figure 8 This is an electron microscope image of the smoke agent microcapsule prepared in Comparative Example 1 of the present invention; Figure 9 This is an electron microscope image of the smoke agent microcapsules prepared in Comparative Example 2 of the present invention; Figure 10 1 is the DTG diagram of Example 1, Example 4 and Comparative Examples 1 to 3 of the present invention; Figure 11 1 and 2 are the particle size distribution curves of Example 1, Example 4, and Comparative Example 1-Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0039] The following is a detailed description of the specific embodiments of the present invention. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention and are not intended to limit the present invention.

[0040] The endpoints of the ranges and any values disclosed herein are not limited to the precise ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0041] In a first aspect, the present invention provides a smoke-generating agent microcapsule, comprising a core material and a wall material, wherein the core material contains a smoke-generating agent and a phase change material, and the phase change material is a crystal.

[0042] During the research process, the inventors of the present invention unexpectedly discovered that the smoke agent microcapsules include a core material and a wall material. The smoke agent contained in the core material can interact with the phase change material through hydrogen bonds to form a eutectic. Its melting peak is relatively single and has a larger specific gravity than that of conventional liquid smoke agents. After reaching the phase change temperature, the eutectic undergoes phase transformation, destroying the microcapsule structure and slowly releasing smoke. The high-temperature resistant wall layer will not decompose, making it safer. Through the coordinated effect of the core material and the wall material, the stability of the smoke agent microcapsules at room temperature can be improved, and the influence of drastic changes in the temperature of the tobacco before and after each puff on continuous smoking can be avoided, thereby delaying the overall smoking process of the tobacco and improving the sustained release effect of the smoke. It can also improve the wall breaking rate of the smoke agent microcapsules under high-temperature heating conditions, so that the smoke agent is released evenly and stably at high temperature, which can further improve the sustained release effect of the smoke and reduce the hygroscopic effect of the smoke agent exposed to the outside, and has significant market prospects.

[0043] According to the present invention, preferably, the peak temperature of the heating curve of the smoke agent microcapsule is T pm The melting point temperature T of the core material m The absolute value of the temperature difference |T pm -T m |≤12.0℃; further preferably, |T pm -T m |≤9.8℃; More preferably, |T pm -T m |≤7.8℃; especially preferably, |T pm -T m |≤4.8℃; More preferably, |T pm -T m ∣≤2.8℃. Peak temperature T of the heating curve of the smoke agent microcapsule pm The melting point temperature T of the core material m When the absolute value of the temperature difference satisfies the above range, the smoke-generating agent microcapsules have good stability at high temperatures and can achieve a slow-release effect of smoke.

[0044] According to the present invention, in order to further improve the stability of the smoke agent microcapsules at room temperature, preferably, |T pm -T m |≤1.8℃; further preferably, |T pm -T m |≤0.9℃; More preferably, |T pm -T m |≤0.5℃; particularly preferably, |T pm -T m ∣≤0.2℃.

[0045] According to the present invention, preferably, the mass ratio of the core material to the wall material in the smoke-generating agent microcapsules is 1.6-3.8:1, specifically 1.6:1, 2:1, 2.5:1, 3:1, 3.8:1, or any value in between. The inventors have discovered that, under this preferred embodiment, the coordinated action of the aforementioned specific amounts of core material and wall material can further improve the stability of the smoke-generating agent microcapsules at room temperature, delay the overall smoking process of tobacco, enhance the sustained release of smoke, and further increase the wall-breaking rate of the smoke-generating agent microcapsules under high-temperature heating conditions.

[0046] According to the present invention, the smoke-generating agent microcapsules preferably have a coverage ratio of 65-90%, specifically 65%, 70%, 75%, 80%, 85%, 90%, or any value in between. Smoke-generating agent microcapsules having such a coverage ratio not only have a good smoke-release effect, but also have good morphology and sealing properties.

[0047] According to the present invention, in order to further improve the stability of the smoke-generating agent microcapsules at room temperature, preferably, the melting point of the phase change material is ≥90°C.

[0048] According to the present invention, preferably, the melting enthalpy ΔH of the phase change material m ≥130 J·g -1 , further preferably, ΔH m ≥160 J·g -1 ; Further preferably, ΔH m ≥180 J·g -1 ; Particularly preferably, ΔH m ≥210 J·g -1 The inventors have found that, under this preferred embodiment, the phase change material having the above-mentioned melting enthalpy can improve the stability of the smoke-generating agent microcapsules at room temperature, thereby delaying the overall smoking process of tobacco.

[0049] According to the present invention, in order to further improve the stability of the smoke-generating agent microcapsules at room temperature, preferably, ΔH m ≥230 J·g -1 ; Further preferably, ΔH m ≥260 J·g -1 ; Further preferably, ΔH m ≥280 J·g -1 ; Particularly preferably, ΔH m ≥310 J·g -1 .

[0050] According to the present invention, to further improve the stability of the smoke-generating agent microcapsules at room temperature, the smoke-generating agent preferably includes a sugar alcohol, wherein the sugar alcohol is selected from at least one of sorbitol, mannitol, erythritol, maltitol, lactitol, and xylitol. The inventors have discovered that this preferred embodiment can increase the wall-breaking rate of the smoke-generating agent microcapsules at high temperatures, thereby further improving the sustained release effect of the smoke.

[0051] According to the present invention, the above substances can all be obtained commercially.

[0052] According to the present invention, preferably, the phase change material includes a first melting point having a lower temperature T m1 The first sugar alcohol and the second sugar alcohol having a higher melting point temperature T m2 The second sugar alcohol, the peak temperature of the heating curve of the smoke-generating agent microcapsule T pm With T m1 、T m2 The relationship is T pm ∈[T m1 ,T m2 The first sugar alcohol and the second sugar alcohol are both selected from one of sorbitol, mannitol, erythritol, maltitol, lactitol, and xylitol. The inventors have found that under this preferred embodiment, the synergistic effect of the first sugar alcohol and the second sugar alcohol further improves the stability of the smoke-generating agent microcapsules at room temperature and the wall-breaking rate under high-temperature heating conditions, thereby further improving the sustained release effect of the smoke.

[0053] According to the present invention, in order to further improve the stability of the smoke-generating agent microcapsules at room temperature and the wall-breaking rate under high-temperature heating conditions, preferably, the smoke-generating agent is selected from at least one of propylene glycol, ethylene glycol, glycerin, vanillin, vanillic acid, vanillyl acrylate, styrene, benzaldehyde, phenylpropanol, acetophenone, nicotine, nicotinic acid and amino acids, and glycerin is more preferably selected.

[0054] According to the present invention, the mass ratio of the smoke generating agent to the phase change material is 1:0.25-4.

[0055] According to the present invention, the wall material preferably comprises a silicone-modified polyurethane, obtained by polymerization of a silicon-containing polyurethane prepolymer and a polyacrylate. The inventors have discovered that, under this preferred embodiment, the wall material comprising silicone-modified polyurethane can improve the thermal stability of the smoke-generating agent microcapsules.

[0056] According to the present invention, in order to further improve the thermal stability of the smoke-generating agent microcapsules, preferably, the polyacrylate is selected from at least one of polyethyl methacrylate, polyethyl methacrylate derivatives, polymethyl methacrylate and polymethyl methacrylate derivatives, and more preferably polyethyl methacrylate.

[0057] According to the present invention, in order to further improve the thermal stability of the smoke-generating agent microcapsules, preferably, the weight average molecular weight of the polyacrylate is 200-10,000, specifically 200, 2,000, 4,000, 6,000, 8,000, 10,000, or any value between the foregoing two values.

[0058] According to the present invention, in order to further improve the efficiency and yield of the polymerization reaction, preferably, the polymerization reaction is carried out in the presence of an initiator.

[0059] According to the present invention, in order to further improve the efficiency and yield of the polymerization reaction, preferably, the initiator is selected from at least one of a peroxide, a sulfur-containing compound, a nitrite, and a lead compound, and more preferably a peroxide. Exemplarily, the initiator is potassium persulfate.

[0060] According to the present invention, in order to further improve the thermal stability of the smoke-generating agent microcapsules, preferably, the silicon-containing polyurethane prepolymer is obtained by mixing silicone, diisocyanate and hydroxyethyl acrylate.

[0061] According to the present invention, in order to further improve the thermal stability of the smoke agent microcapsules, preferably, the silicone is selected from at least one of dimethyl silicone oil, hydroxy silicone oil, silane, silicone, polysiloxane, long-chain alkyl silicone oil, amino silicone oil and amide silicone oil, and more preferably hydroxy silicone oil.

[0062] According to the present invention, in order to further improve the thermal stability of the smoke agent microcapsules, preferably, the weight average molecular weight of the silicone is 200-10,000, specifically 200, 2,000, 4,000, 6,000, 8,000, 10,000, or any value between the foregoing two values.

[0063] According to the present invention, in order to further improve the thermal stability of the smoke-generating agent microcapsules, preferably, the diisocyanate is selected from at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate, and is more preferably isophorone diisocyanate.

[0064] According to the present invention, in order to further improve the efficiency and yield of the mixed reaction, preferably, the mixed reaction is carried out in the presence of an organotin catalyst and an organic solvent.

[0065] According to the present invention, in order to further improve the efficiency and yield of the mixing reaction, preferably, the organotin catalyst is selected from at least one of dibutyltin dilaurate, dibutyltin diacetate and stannous octoate.

[0066] According to the present invention, in order to further improve the efficiency and yield of the mixed reaction, preferably, the organic solvent is selected from at least one of tetrahydrofuran, xylene and n-butyl acetate.

[0067] According to the present invention, in order to further improve the thermal stability of the smoke-generating agent microcapsules, preferably, the structure of the silicon-containing polyurethane prepolymer is as shown in formula (I); Formula (I); wherein R1 is selected from C6-10 alkylene and C6-C14 arylene, and n is an integer greater than 3; illustratively, the C6-10 alkylene can be hexylene, heptylene, octylene, nonylene, decylene, or C6-C10 cycloalkylene, etc.; the C6-C14 arylene can be C6 arylene, C7 arylene, C8 arylene, C9 arylene, C10 arylene, etc.

[0068] In the present invention, the smoke-generating agent microcapsules can be prepared by any microcapsule preparation method. Preferably, the smoke-generating agent microcapsules are prepared by at least one method selected from the group consisting of spray drying, emulsion polymerization, coacervation, in-situ polymerization, and sol-gel methods.

[0069] According to the present invention, preferably, the method for preparing the smoke agent microcapsules comprises the following steps: (1) In the presence of a precipitant, a smoke generating agent and a phase change material are mixed to prepare a smoke generating agent-phase change material eutectic by utilizing the anti-solvent effect; in the presence of an initiator, a silicon-containing polyurethane prepolymer, methyl acrylate and the smoke generating agent-phase change material eutectic are mixed and reacted to obtain an oil phase; a surfactant is dissolved in water to obtain an aqueous phase; (2) mixing the oil phase and the water phase and emulsifying them to obtain an emulsion, and performing mixing reaction II on the emulsion and then demulsifying it; (3) Separate, wash and dry the mixed liquid after demulsification.

[0070] According to the present invention, there is no particular limitation on the amounts of the silicon-containing polyurethane prepolymer, acrylate and smoke-generating agent. In order to further improve the wall breaking rate of the smoke-generating agent microcapsules under high-temperature heating conditions and reduce the hygroscopicity of the smoke-generating agent, preferably, in step (1), the weight ratio of the silicon-containing polyurethane prepolymer, the acrylate and the smoke-generating agent is 1:2-10:10-20.

[0071] According to the present invention, preferably, the weight ratio of the combined weight of the silicon-containing polyurethane prepolymer and the acrylate to the weight of the smoke-generating agent is 1:1.6-3.8, and specifically can be 1.5:1, 2:1, 2.5:1, 3:1, or any value in between. The inventors have discovered that this preferred embodiment can further enhance the sealing properties of the smoke-generating agent microcapsules while increasing the smoke-generating agent encapsulation efficiency, thereby improving the sustained release of smoke.

[0072] According to the present invention, in order to further improve the efficiency and yield of the mixed reaction I, preferably, the conditions of the mixed reaction I include at least: a temperature of 20-90°C, specifically 20°C, 50°C, 70°C, 90°C, or any value between the foregoing two values; a time of 20-40 min, specifically 20 min, 30 min, 40 min, or any value between the foregoing two values.

[0073] In the present invention, the surfactant may be a surfactant conventionally selected in the art, for example, the surfactant may be sodium lauryl sulfate, polyoxyethylene octylphenol ether, sodium lauryl polyoxyethylene ether sulfate, cocamidopropyl betaine, potassium lauryl ether phosphate, etc. In order to further improve the emulsification effect of the oil phase and the aqueous phase, preferably, the surfactant is sodium lauryl sulfate and / or polyoxyethylene octylphenol ether; more preferably, the surfactant is sodium lauryl sulfate and polyoxyethylene octylphenol ether.

[0074] For example, when the surfactant is sodium lauryl sulfate and polyoxyethylene octylphenol ether, the weight ratio of sodium lauryl sulfate to polyoxyethylene octylphenol ether can be 1-3:1, specifically 1:1, 2:1, 3:1, or any value between the foregoing two values.

[0075] According to the present invention, to further improve the emulsification effect of the oil phase and the aqueous phase, preferably, the concentration of the surfactant in the aqueous phase is 0.1-4 wt %, specifically 0.1 wt %, 1 wt %, 2 wt %, 3 wt %, 4 wt %, or any value in between. For example, the aqueous phase can be prepared by uniformly mixing 1-40 parts of the surfactant with 1000 parts of water.

[0076] According to the present invention, in order to further improve the emulsification effect of the oil phase and the water phase, in step (2), the mixing process of the oil phase and the water phase includes: adding the oil phase dropwise into the water phase.

[0077] According to the present invention, in order to further improve the emulsification effect of the oil phase and the water phase, preferably, in step (2), the emulsification conditions include at least: a rotation speed of 3000-10000 rpm, specifically 3000 rpm, 5000 rpm, 8000 rpm, 10000 rpm, or any value between the foregoing two values; a temperature of 40-60°C, specifically 40°C, 50°C, 60°C, or any value between the foregoing two values; and a time of 10-20 min, specifically 10 min, 15 min, 20 min, or any value between the foregoing two values.

[0078] According to the present invention, in order to further improve the efficiency and yield of the mixed reaction II, preferably, in step (2), the conditions of the mixed reaction II include at least: an inert gas, which may be nitrogen; a temperature of 40-95°C, specifically 40°C, 60°C, 80°C, 95°C, or any value between the foregoing two values; and a time of 1-4h, specifically 1h, 2h, 3h, 4h, or any value between the foregoing two values.

[0079] In the present invention, the emulsion can be demulsified by using a demulsifier conventionally selected in the art, and the demulsifier can be an ionic demulsifier or a non-ionic demulsifier. Preferably, the demulsifier is ethanol, more preferably anhydrous ethanol.

[0080] According to the present invention, the above substances can all be obtained commercially.

[0081] In the present invention, separation can be performed by a conventional separation method in the art, such as filtration, suction filtration, centrifugation, etc.; drying can also be performed by a conventional drying method in the art, such as forced air drying, vacuum drying, etc.

[0082] According to the present invention, in step (1), the preparation process of the silicon-containing polyurethane prepolymer includes the following steps: S1. In the presence of an organotin catalyst, mixing organosilicon and diisocyanate to carry out reaction III; S2. In the presence of an organic solvent, conducting a mixing reaction IV with the product of the mixing reaction III and hydroxyethyl acrylate; S3, drying the product of the mixed reaction IV and separating it.

[0083] According to the present invention, in order to further improve the efficiency and yield of the mixed reaction III, the conditions of the mixed reaction III include at least: inert gas protection, the inert gas can be nitrogen; the temperature is 30-95°C, specifically 30°C, 60°C, 95°C, or any value between the foregoing two values; the time is 1-4h, specifically 1h, 2h, 3h, 4h, or any value between the foregoing two values.

[0084] According to the present invention, in order to further improve the efficiency and yield of the mixing reaction III, the weight ratio of the organosilicon, the diisocyanate and the organotin catalyst is 100:1-50:1-10.

[0085] According to the present invention, in order to further improve the efficiency and yield of the mixed reaction IV, preferably, the weight ratio of the organosilicon, hydroxyethyl acrylate, and organic solvent is 100:1-50:1-200.

[0086] According to the present invention, in order to further improve the yield and purity of the silicon-containing polyurethane prepolymer, preferably, in step S3, the separation process includes: extracting the dried product of the mixed reaction IV using n-hexane as a solvent, and then drying.

[0087] According to a particularly preferred embodiment of the present invention, a smoke agent microcapsule is provided, the smoke agent microcapsule comprises a core material and a wall material, the core material contains a smoke agent and a phase change material, the phase change material is a crystal; the peak temperature T of the heating curve of the smoke agent microcapsule is pm The melting point temperature T of the core material m The absolute value of the temperature difference |T pm -T m ∣≤0.2℃; the mass ratio of the core material to the wall material in the smoke agent microcapsule is 1.6-3.8:1; the coverage rate of the smoke agent microcapsule is 65-90%; the melting point of the phase change material is ≥90℃; the melting enthalpy of the phase change material ΔH m ≥310 J·g -1 The phase change material is selected from at least one of sorbitol, mannitol, erythritol, maltitol, lactitol and xylitol; the smoke generating agent is glycerol; The wall material contains organosilicon-modified polyurethane, which is obtained by polymerization reaction of a silicon-containing polyurethane prepolymer and a polyacrylate; the polyacrylate is polyethyl methacrylate, and the weight-average molecular weight of the polyacrylate is 200-10,000; the silicon-containing polyurethane prepolymer is obtained by mixing organosilicon, diisocyanate and hydroxyethyl acrylate; the organosilicon is hydroxy silicone oil, and the weight-average molecular weight of the organosilicon is 200-10,000; the diisocyanate is isophorone diisocyanate; the organotin catalyst is selected from at least one of dibutyltin dilaurate, dibutyltin diacetate and stannous octoate; and the organic solvent is n-butyl acetate. The structure of the silicon-containing polyurethane prepolymer is shown in formula (I); Formula (I); Wherein, R1 is selected from C6-10 alkylene and C6-C14 arylene, and n is an integer greater than 3.

[0088] In the above particularly preferred embodiment, the smoke agent microcapsules have high stability at room temperature and can delay the overall smoking process of tobacco; they can also increase the wall breaking rate of the smoke agent microcapsules under high-temperature heating conditions, so that the smoke agent is released evenly and stably at high temperatures, which can significantly achieve a sustained release effect of smoke while reducing the hygroscopic effect of the smoke agent exposed to the outside.

[0089] In a second aspect, the present invention provides a heated cigarette, comprising the smoking agent microcapsules described in the first aspect.

[0090] According to the present invention, the heated cigarette paper can be applied to a heated smoking device, which includes a heater close to a smoking portion to heat the smoking portion.

[0091] In the present invention, the term "heating device" as an aerosol-generating device is used to describe a device that interacts with the aerosol-forming matrix of an aerosol-generating article to generate aerosols. The heating method of the smoking device can utilize the principles of resistance heating, infrared heating, and electromagnetic induction heating. Resistance heating mainly includes internal core heating, external heating, and internal and external combined heating. Infrared heating mainly includes external heating. The heater can also be placed in the aerosol-generating article. When the aerosol-generating article is connected to the smoking device, the heater is electrically connected to the smoking device. The heater is preferably needle-shaped, strip-shaped, leaf-shaped, or tubular. For internal heating, the capsules can be concentrated on the outermost side of the aerosol-generating matrix or on the cigarette paper. For external heating, the capsules can be concentrated near the axis of the aerosol-generating matrix, away from the heater, to achieve a better sustained-release effect.

[0092] According to the present invention, in order to further delay the smoking process of tobacco and improve the sustained release effect of tobacco, preferably, the heated cigarette includes a smoking part and a filtering part, and the smoking agent microcapsules are arranged in the smoking part.

[0093] According to the present invention, the smoking portion further comprises an aerosol-forming substrate comprising tobacco components. The aerosol-forming substrate is primarily a solid aerosol-forming substrate, which may include both solid and liquid components. The solid aerosol-forming substrate may comprise one or more of a powder, granules, pellets, fragments, strips, bars, or sheets, and may comprise at least one of herbaceous plant leaves, tobacco leaves, tobacco ribs, flat tobacco, and homogenized tobacco.

[0094] In the present invention, an aerosol-forming matrix comprising a homogenized tobacco sheet for use in an aerosol-generating product can be manufactured using existing manufacturing processes in the art, such as a roller pressing method, a thick slurry method, and a papermaking method. During this process, smoke-generating microcapsules can be incorporated into the aerosol-generating matrix as part of the raw materials, so that the smoke-generating microcapsules are formed within the homogenized tobacco sheet. Alternatively, the smoke-generating microcapsules can be adhered to the surface of the homogenized tobacco sheet using an adhesive, preferably a pressure-sensitive adhesive. The smoke-generating microcapsules can be locally adhered to the surface of the homogenized tobacco sheet. When the homogenized tobacco sheet is wrinkled and gathered, the smoke-generating microcapsules can be concentrated at the outermost side or near the axis of the aerosol-generating matrix, thereby away from the smoking device heater used with the cigarette, achieving a better sustained-release effect.

[0095] According to the present invention, preferably, the filter portion comprises a supporting element, an aerosol cooling element and a mouthpiece, and the supporting element, the aerosol cooling element and the mouthpiece are sequentially connected along the length direction of the heated cigarette.

[0096] According to the present invention, the maximum temperature of the smoke generating portion heated by the heater does not exceed 350°C. Preferably, the smoke generating agent microcapsules have a thermal decomposition mass loss rate of 40% or more at a temperature not higher than 350°C. Smoke generating agent microcapsules having a high thermal decomposition mass loss rate have good thermal stability at high temperatures.

[0097] According to the present invention, in order to further delay the smoking process of tobacco and improve the sustained release effect of tobacco, preferably, the heated cigarette further includes cigarette paper wrapping the smoking part, and the smoking agent microcapsules are arranged on the cigarette paper.

[0098] The present invention is described in detail below with reference to the embodiments, but the scope of the present invention is not limited thereby.

[0099] In the following examples and comparative examples, hydroxy-terminated silicone oil was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. with a molecular weight of 2000 g / mol; isophorone diisocyanate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. with a purity of 99.0%, an isomer mixture; dibutyltin dilaurate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. with a purity of 95.0%; hydroxyethyl acrylate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. with a purity of 96.0%; n-butyl acetate was purchased from Beijing Bailingwei Technology Co., Ltd. with a purity of 99.0%; n-hexane was purchased from Sinopharm Chemical Reagent Co., Ltd. with a purity of not less than 97.0%; polymethyl methacrylate was purchased from Sinopharm Chemical Reagent Co., Ltd. with a molecular weight of 15000 g / mol and a purity of not less than 98.0%; sodium lauryl sulfate was purchased from Beijing Wokai Biotechnology Co., Ltd. with a purity of 90.0%; polyoxyethylene octylphenol ether-10 was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., which is hydrophilic and has a hydroxyl value of 87 10; maltitol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., with a purity of not less than 98.0%; phase-change paraffin-64 was purchased from Shanghai Future Industrial Co., Ltd., with a phase transition temperature of 64°C. Unless otherwise specified, other raw materials were commercially available.

[0100] In the following examples and comparative examples, a high shear emulsifier was purchased from Shanghai Fluke Technology Development Co., Ltd., model FA25; a vacuum ion sputtering metallurgist was purchased from Quorum Technologies Ltd., model SC7620; a scanning electron microscope (SEM) was purchased from Thermo Fisher Scientific, model ProX; and a differential scanning calorimeter was purchased from Waters Technology (Shanghai) Co., Ltd., model DSC25.

[0101] Preparation Example 1 (1) Place 50g of hydroxyl-terminated silicone oil and 10g of isophorone diisocyanate in a four-necked flask equipped with a stirrer and a spherical condenser; add 0.5% by mass of dibutyltin dilaurate as a catalyst, introduce nitrogen, and move the four-necked flask to a 60°C water bath for 2.5h to allow the hydroxyl groups in the hydroxyl silicone oil to react with the isocyanate in the isophorone diisocyanate; (2) Then, 10 g of hydroxyethyl acrylate and 100 g of n-butyl acetate were added and reacted for 2 h to obtain a double-bond terminated silicon-containing polyurethane prepolymer solution. Subsequently, the silicon-containing polyurethane prepolymer solution was placed in a vacuum drying oven and dried at 70°C for 72 h. Then, it was extracted with n-hexane as a solvent for 24 h and dried at 70°C for 72 h to obtain a silicon-containing polyurethane prepolymer.

[0102] The preparation process of the silicon-containing polyurethane prepolymer in Preparation Example 1 is as follows: Figure 1 shown.

[0103] Preparation Example 2 A silicon-containing polyurethane prepolymer was prepared according to the method of Preparation Example 1, except that isophorone diisocyanate was replaced by toluene diisocyanate.

[0104] Preparation Example 3 A silicon-containing polyurethane prepolymer was prepared according to the method of Preparation Example 1, except that isophorone diisocyanate was replaced by hexamethylene diisocyanate.

[0105] Preparation Example 4 S1. Prepare a glycerol aqueous solution with a glycerol concentration of 60 wt%, heat it to 80°C, add maltitol (the mass of maltitol is 20% of the glycerol aqueous solution), and fully dissolve it to obtain a maltitol-glycerol solution; S2, using cold (4°C) ethanol (1:2 volume ratio with water) as a precipitant; S3. Nanocrystal formation: The maltitol-glycerol solution (70°C) in step S1 was rapidly injected into the pre-cooled precipitant in step S2 (magnetic stirring speed was 1000 rpm), and the anti-solvent effect was used to induce the instantaneous precipitation of maltitol-glycerol nano-cocrystals. The maltitol-glycerol nano-cocrystals were obtained by centrifugation, filtration, ethanol washing, and freeze-drying at -20°C for 24 hours.

[0106] Preparation Example 5 Maltitol-sorbitol-glycerol nanoco-crystals were prepared according to the method of Preparation Example 4, except that the maltitol in step S1 was replaced by maltitol and isosorbide (mass ratio of 1:1).

[0107] Preparation Example 6 Maltitol-erythritol-glycerol nanoco-crystals were prepared according to the method of Preparation Example 4, except that the maltitol in step S1 was replaced by maltitol and erythritol (mass ratio of 1:2.6).

[0108] Preparation Example 7 Erythritol-glycerol nano-co-crystals were prepared according to the method of Preparation Example 4, except that the maltitol in step S1 was replaced by erythritol.

[0109] Preparation Example 8 Sorbitol-glycerol nanoco-crystals were prepared according to the method of Preparation Example 4, except that the maltitol in step S1 was replaced by sorbitol.

[0110] Preparation Example 9 Xylitol-glycerol nano-co-crystals were prepared according to the method of Preparation Example 4, except that the maltitol in step S1 was replaced by xylitol.

[0111] Preparation Example 10 Maltitol-propylene glycol nano-co-crystals were prepared according to the method of Preparation Example 4, except that the glycerol aqueous solution in step S1 was replaced by a 60 wt % propylene glycol aqueous solution.

[0112] Example 1 2.0 g of the silicon-containing polyurethane prepolymer obtained in Preparation Example 1, 10 g of polymethyl methacrylate, 20 g of the maltitol-glycerol nano-cocrystal obtained in Preparation Example 4, and 0.2 g of potassium persulfate were stirred at 50° C. for 20 min and mixed evenly to form the oil phase; 1.0 g of sodium lauryl sulfate and 0.5 g of polyoxyethylene octylphenol ether-10 were added to 160 g of deionized water, stirred at 40° C. for 20 min, and mixed evenly to form the aqueous phase; the oil phase was added dropwise to the aqueous phase at 40° C. and stirred at 8000 r / min for 10 min using a high shear emulsifier to form a stable emulsion; nitrogen was introduced into a four-necked flask, and the stable emulsion was poured into the four-necked flask and reacted at 70° C. for 2.5 h; after the reaction, anhydrous ethanol was used to break the emulsion, and the mixture was filtered, washed with deionized water, and dried to obtain smoke-generating agent microcapsules with the maltitol-glycerol nano-cocrystal as the core material and the silicone-modified polyurethane as the wall material.

[0113] Example 2 2.0g of the silicon-containing polyurethane prepolymer obtained in Preparation Example 2, 6g of polymethyl methacrylate, 20g of the maltitol-sorbitol-glycerol nano-cocrystal obtained in Preparation Example 5, and 0.2g of potassium persulfate were stirred at 30°C for 40min and mixed evenly as the oil phase; 1.0g of sodium lauryl sulfate and 0.5g of polyoxyethylene octylphenol ether-10 were added to 160g of deionized water, stirred at 40°C for 20min, and mixed evenly as the water phase. ; Add the oil phase dropwise into the aqueous phase at 40°C, and use a high-shear emulsifier to stir at a speed of 10,000 r / min for 10 minutes to form a stable emulsion; nitrogen is introduced into a four-necked flask, and then the stable emulsion is poured into the four-necked flask, and reacted at 50°C for 4 hours; after the reaction is completed, use anhydrous ethanol to break the emulsion, filter, wash with deionized water, and dry to obtain smoke-generating agent microcapsules with maltitol and sorbitol as core materials and silicone-modified polyurethane as wall materials.

[0114] Example 3 2.0 g of the silicon-containing polyurethane prepolymer obtained in Preparation Example 3, 15 g of polymethyl methacrylate, 36 g of the maltitol-erythritol-glycerol nano-cocrystal obtained in Preparation Example 6, and 0.2 g of potassium persulfate were stirred at 70° C. for 30 min and mixed evenly to form the oil phase; 1.0 g of sodium lauryl sulfate and 0.5 g of polyoxyethylene octylphenol ether-10 were added to 160 g of deionized water, stirred at 40° C. for 20 min, and mixed evenly to form the aqueous phase; the oil phase was added dropwise to the aqueous phase at 40° C. and stirred at 6000 r / min for 20 min using a high shear emulsifier to form a stable emulsion; nitrogen was introduced into a four-necked flask, and the stable emulsion was poured into the four-necked flask and reacted at 90° C. for 1 h; after the reaction, anhydrous ethanol was used to break the emulsion, and the mixture was filtered, washed with deionized water, and dried to obtain smoke-generating agent microcapsules with maltitol as the core material and silicone-modified polyurethane as the wall material.

[0115] Example 4 Smoking agent microcapsules were prepared according to the method of Example 1, except that the amount of maltitol-glycerol nano-cocrystals was replaced with 30 g.

[0116] Example 5 Smoking agent microcapsules were prepared according to the method of Example 1, except that 20 g of maltitol-glycerol nano-co-crystals were replaced with 30 g of erythritol-glycerol nano-co-crystals obtained in Preparation Example 7.

[0117] Example 6 Smoking agent microcapsules were prepared according to the method of Example 1, except that 20 g of maltitol-glycerol nano-co-crystals were replaced with 30 g of sorbitol-glycerol nano-co-crystals obtained in Preparation Example 8.

[0118] Example 7 Smoking agent microcapsules were prepared according to the method of Example 1, except that 20 g of maltitol-glycerol nano-co-crystals were replaced with 30 g of xylitol-glycerol nano-co-crystals obtained in Preparation Example 9.

[0119] Example 8 Smoking agent microcapsules were prepared according to the method of Example 1, except that the amount of maltitol-glycerol nano-cocrystals was replaced with 40 g.

[0120] Example 9 Smoking agent microcapsules were prepared according to the method of Example 1, except that the amount of silicon-containing polyurethane prepolymer was replaced with 3 g.

[0121] Example 10 Smoking agent microcapsules were prepared according to the method of Example 1, except that the maltitol-glycerol nano-co-crystals were replaced by the maltitol-propylene glycol nano-co-crystals obtained in Preparation Example 10.

[0122] Example 11 Smoking agent microcapsules were prepared according to the method of Example 1, except that the silicon-containing polyurethane prepolymer was replaced with a gelatin-gum arabic composite wall material. The preparation process of the gelatin-gum arabic composite wall material included the following steps: (I) Prepare 50 g of a 5% aqueous gelatin solution and 50 g of a 5% aqueous gum arabic solution, place them in separate containers, preheat in a 40°C water bath, and stir until uniform; (II) The gelatin aqueous solution and the gum arabic aqueous solution were mixed in a four-necked flask with a stirrer at a speed of 200 r / min, and then the pH was adjusted to 4.0-4.5 with 10% acetic acid solution. At this time, the two polymers underwent complex coagulation. (III) The reaction system was cooled to about 10° C., 2 g of glutaraldehyde was added as a cross-linking agent, and the reaction was continued with stirring for 3 h to further cross-link and solidify the gelatin-gum arabic complex.

[0123] Example 12 Smoking agent microcapsules were prepared according to the method of Example 1, except that the silicon-containing polyurethane prepolymer was replaced with a urea-formaldehyde resin prepolymer. The preparation process of the urea-formaldehyde resin prepolymer included the following steps: (I) In a four-necked flask equipped with a stirrer and a condenser, 30 g of urea and 60 g of a 37% formaldehyde solution were added, and the pH was adjusted to 8.5 ± 0.5 with sodium hydroxide solution; (II) The flask was placed in a 60°C water bath for 1 hour to allow urea and formaldehyde to undergo an addition reaction to form a urea-formaldehyde resin prepolymer.

[0124] Comparative Example 1 Smoking agent microcapsules were prepared according to the method of Example 1, except that 20 g of maltitol-glycerol nano-cocrystals were replaced with 30 g of phase change paraffin-64.

[0125] Comparative Example 2 Smoking agent microcapsules were prepared according to the method of Example 1, except that 20 g of maltitol-glycerol nano-cocrystals were replaced by 30 g of phase change paraffin-64, and the amount of silicon-containing polyurethane prepolymer was replaced by 4 g.

[0126] Comparative Example 3 Take 30g of untreated maltitol.

[0127] Test Example 1 After the smoke agent microcapsules prepared in Example 1, Example 4, Example 5, Example 6, Example 7, Example 8, Comparative Example 1 and Comparative Example 2 were sprayed with gold, their morphologies were observed using a scanning electron microscope. The scanning electron microscope results showed that Figure 2-Figure 9 .

[0128] from Figure 2 、 Figure 3 and Figure 7 It can be seen that the overall particle size of the smoke-generating agent microcapsules increases with the amount of maltitol-glycerol nano-eutectic, with the average particle size rising from 3.2μm, 5.4μm, to 7.2μm. When the amount of maltitol-glycerol nano-eutectic is 20g (Example 1) and 30g (Example 4), the resulting shell is relatively dense and homogeneous. However, when the amount of maltitol-glycerol nano-eutectic is increased to 40g (Example 8), the resulting smoke-generating agent microcapsules further improve the smoke-generating agent encapsulation efficiency, but the shell softens, resulting in poor sealing and dispersibility. Therefore, considering factors such as microcapsule morphology, smoke-generating agent encapsulation efficiency, and sealing, the optimal microcapsule core-to-wall ratio is between 1.5:1 and 3:1.

[0129] from Figure 4 、 Figure 5 、 Figure 6 、 Figure 8 and Figure 9 It can be seen that compared with Comparative Examples 1-2, Examples 5-7 use smoke-generating agent microcapsules with different core materials. When the core material dosage is 30 g, they all present a dense and homogeneous microcapsule morphology, reflecting that the core material selection of the preparation method of the present invention is universal; and their particle sizes are relatively close, and their average particle sizes are: 4.8μm, 5.7μm, 5.9μm, 5.3μm, and 5.8μm, respectively.

[0130] Test Example 2 The smoke-generating agent microcapsules obtained in Examples 1-12 and Comparative Examples 1-2 were tested using the following method: 5-8 mg of sample was placed in a crucible and heated from -20°C to 150°C at a heating rate of 5°C / min using a differential scanning calorimeter (DSC). The sample was then held at 100°C for 5 minutes and then cooled from 100°C to -20°C at the same cooling rate. The DSC results of the smoke-generating agent microcapsules are shown in Table 1.

[0131] Table 1

[0132] In Table 1, T om T is the starting temperature of the endothermic peak of the heating curve; pm is the peak temperature of the heating curve; ΔH m is the enthalpy value of the heating curve; Toc T is the starting temperature of the endothermic peak of the cooling curve; pc is the peak temperature of the cooling curve; ΔH c is the enthalpy of the cooling curve.

[0133] From the DSC heating curve, the coverage rate can be calculated according to the phase change enthalpy of the microcapsules:

[0134] in, is the phase change enthalpy of the microcapsule (J / g), is the phase change enthalpy of the phase change wax ( J / g ).

[0135] As a reference, the melting point temperature and phase change enthalpy of maltitol, erythritol, sorbitol, xylitol, and phase change paraffin-64 were determined using the same method. The results are shown in Table 2.

[0136] Table 2

[0137] Example 1: The core material is maltitol-glycerol nano-co-crystal, and the wall material is silicone-modified polyurethane + polymethyl methacrylate (PMMA). DSC data shows that the melting peak temperature T pm The melting enthalpy ΔH m The core-wall ratio is 1.67:1, which optimizes the core material dispersion and wall material coverage.

[0138] Example 2: Using maltitol-sorbitol-glycerol nano-co-crystals as the core material. pm Between maltitol and sorbitol, the eutectic effect makes the phase transition temperature adapt to the medium temperature scene; however, due to the multi-component eutectic weakening the crystal order, ΔH m The coverage rate was 84.0%, slightly lower than that of Example 1, which may be due to the complicated interface compatibility of the multi-component core material.

[0139] Example 3: Using maltitol-erythritol-glycerol nano-co-crystals as the core material, high proportion of erythritol dominates the thermal response, T pm 69.9% close to the melting point of erythritol; its high melting point but low enthalpy value makes ΔH m The coating efficiency was 82.50%. The high melting point of erythritol affected the dispersion uniformity of the core material, but it was still better than the paraffin system.

[0140] Example 4: Increasing the amount of maltitol-glycerol nano-co-crystal core material, T pmFurther reduction, Δ m The increase indicates that the increase in the proportion of core material enhances the energy storage capacity. The coverage rate reaches 92.00%, indicating that the coverage efficiency is optimal when the core-to-wall ratio is ≤ 1.

[0141] Example 5-Example 7: Replacing the core material with different sugar alcohol-glycerol co-crystals, T pm Increase successively, Δ times m The encapsulation efficiency varies with the water solubility and emulsification stability of sugar alcohols, with erythritol > sorbitol > xylitol.

[0142] Example 8: ΔH under high core material load m Reached the highest, but T pm The thermal stability of the shell is significantly reduced due to excessive core material, and the shell softens and thermal stability decreases. Although the coverage rate reaches 95.0%, the risk of core material overflow is high, which limits its practical application.

[0143] Example 9-Example 10: Example 9 reduces the amount of wall material used, and the coverage rate and energy storage efficiency are slightly reduced; Example 10 replaces glycerol with propylene glycol, T pm The low boiling point of propylene glycol affects the high temperature stability and the coverage rate is also reduced.

[0144] Examples 11-12: Using non-silicon-based wall materials, gelatin-gum arabic and urea-formaldehyde resin achieved relatively low encapsulation rates of 72.3% and 68.5%, respectively. Natural wall materials have poor sealing properties, and rigid wall materials are brittle, leading to core material leakage or microcapsule rupture.

[0145] The energy storage capacity of the phase-change paraffin wax in Comparative Examples 1-2 is only 50-60% of that of the sugar alcohol system, and the coverage rate is ≤72.00%; the thermal response of the uncoated maltitol in Comparative Example 3 is uncontrollable.

[0146] Based on the above analysis, sugar alcohol co-crystallization can accurately control the phase transition temperature between 60-90℃, with a decrease of 30-70℃, and ΔH m It can maintain 60-80% of the pure material. The comprehensive performance of maltitol-glycerol (1:1) nano-co-crystal is the best; the higher the proportion of erythritol, the better the T pm The closer to its melting point, the lower the coverage.

[0147] In addition, silicone-modified polyurethane has the best performance, followed by urea-formaldehyde resin, and gelatin-gum arabic has the worst performance. Silicon-based wall materials have advantages in flexibility and interfacial bonding strength, with a coverage rate of >80%. When the core-to-wall ratio is 1.5:1-2.5:1, the coverage rate and thermal stability are the best; when the core-to-wall ratio is >3:1, the shell softens, limiting its practical application. mCompared to paraffin wax systems, the coating rate is 40-80% higher, with a 15-25% higher coverage rate, making it suitable for applications requiring high energy storage, such as fire smoke generators. High-melting-point sugar alcohols (such as erythritol) require optimized emulsification and dispersion processes; non-silicone-based wall materials can be cross-linked to improve sealing.

[0148] In addition, due to the strong interaction between sugar alcohol molecules, the phase transition enthalpy (ΔH m ) significantly improved, resulting in the prepared smoke-generating agent microcapsules exhibiting superior energy storage and sustained-release properties. Therefore, the present invention prefers sugar alcohols with high phase transition enthalpy as core materials based on their thermophysical properties during phase transition and their contribution to the overall performance of the microcapsules.

[0149] Test Example 3 Thermal decomposition experiments were performed on the smoke-generating agent microcapsules prepared in Example 1, Example 4, and Comparative Examples 1 to 3.

[0150] The instrument used for the thermal decomposition experiment was a TGA2 thermogravimetric analyzer, an open alumina crucible was used, and the experimental atmosphere was N2 at a flow rate of 50 mL / min. Different samples (2.5 mg ± 0.2 mg) were taken and placed in the alumina crucible. Different heating rates of 5, 10, and 15 ° C / min were used. The heating range used in the experiment was 30-800 ° C. The changes in sample mass before and after the experiment were compared to observe the thermal decomposition characteristics. The results are shown in Figure 10 .

[0151] from Figure 10 It can be seen that the mass fraction of the microcapsules in Comparative Example 3 begins to decrease significantly at around 200°C, and only a small amount remains at 300°C.

[0152] from Figure 10It can be seen that the thermal decomposition process of the four microcapsules in Example 1, Example 4, Comparative Example 1, and Comparative Example 2 is divided into two stages: the first stage is attributed to heat release from the core material; the second stage is caused by thermal decomposition of the wall material. Specifically, the first stage of thermal decomposition in Example 1 and Example 4 occurs primarily in the temperature range of 200-350°C, while the second stage of thermal decomposition is concentrated between 350-400°C. At 350°C, the mass loss rates of Example 1 and Example 4 reached 48.8% and 61.2%, respectively. This difference is primarily due to the different amounts of maltitol-glycerol nano-cocrystal core material used in the two microcapsules. Comparative Examples 1 and 2 use paraffin as the core material. Due to its higher boiling point, paraffin wax hardly decomposes significantly below 300°C. At 400°C, the mass loss rates of the two examples reached 68.6% and 47.2%, respectively, indicating that a large amount of residue still exists. In particular, in Comparative Example 2, the inclusion of a higher proportion of silicon-containing prepolymer in the wall material resulted in a higher degree of crosslinking, significantly improving the thermal stability of the microcapsule wall material. Furthermore, the bond energy of the Si-O bond (451.4 kJ / mol) was significantly higher than the C-C bond energy of the conventional wall material (355.3 kJ / mol). This difference demonstrates that the introduction of Si-O bonds significantly enhances the heat resistance of the microcapsule wall material. Therefore, while silicon-containing polyurethane prepolymers offer greater safety, controlling the wall material thickness is crucial to ensure maximum thermal decomposition below 350°C. Precisely controlling the degree of crosslinking in the wall material can further enhance the heat resistance of the microcapsule wall layer. Furthermore, by adjusting the amount and type of core material, the thermal decomposition temperature of the microcapsules can be adjusted to meet specific application needs. In this invention, maltitol was selected as an ideal core material within the heating range of heated cigarettes due to its decomposition temperature above 200°C and its high degree of decomposition within 300°C. In addition, the preferred microcapsule core-to-wall weight ratio is controlled within the range of 1.6-3.8:1 to achieve the best performance balance.

[0153] Test Example 4 The smoke-generating agent microcapsules prepared in Examples 1 to 12 and Comparative Example 1 were subjected to a smoking experiment.

[0154] The smoking experiment process: The smoking agent microcapsules prepared in Examples 1 to 12 and Comparative Example 1 were respectively mixed with shredded tobacco from the iQOS ILUMA heated cigarette at a mass ratio of 0.05:1 to form tobacco segments. Heated cigarettes were made according to the original weight of the iQOS ILUMA heated cigarettes. Using the iQOS ILUMA heated cigarettes as a reference, tobacco tasters used iQOS ILUMA heating devices to heat and smoke the cigarettes. With reference to "GB5606.4-2005 Cigarettes Part 4 Sensory Technical Requirements", "YC / T564-2018 Sensory Evaluation Method for Chinese Cigarettes Based on Consumer Experience", and "YC / T 497-2014 Sensory Evaluation Method for Chinese Cigarette Style", and in combination with the smoke characteristics of the heated cigarettes, key evaluation indicators (Table 3) were formulated. Sensory evaluations were conducted and the evaluation scores were recorded according to the table below. The results are shown in Table 4.

[0155] Table 3

[0156] Table 4

[0157] As can be seen from the results in Table 4, the smoke yield and uniformity of Comparative Examples 1 and 2 failed to achieve the expected results; since the maltitol in Comparative Example 3 was not encapsulated and was simply mixed with shredded tobacco, although the smoke yield was high, the uniformity was insufficient; Examples 1- and 9, by adopting the sugar alcohol microcapsule atomizer of the present invention, significantly improved the smoke yield and puff uniformity while maintaining the original sensory indicators of the heated cigarette.

[0158] Test Example 5 The particle size distribution of Example 1, Example 4 and Comparative Example 1-Comparative Example 2 was tested, and the results were as follows: Figure 11 shown.

[0159] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, various simple variations of the technical solution of the present invention may be made, including combining the various technical features in any other appropriate manner. These simple variations and combinations should also be regarded as disclosed in the present invention and fall within the scope of protection of the present invention.

Claims

1. A smoke-generating agent microcapsule, characterized in that: The smoke-generating agent microcapsule comprises a core material and a wall material. The core material contains a smoke-generating agent and a phase-change material. The phase-change material is a crystal.

2. The smoke generating agent microcapsule according to claim 1, characterized in that The peak temperature T of the heating curve of the smoke agent microcapsule pm The melting point temperature T of the core material m The absolute value of the temperature difference |T pm -T m |≤12.0℃; preferably, |T pm -T m |≤9.8℃; further preferably, |T pm -T m |≤7.8℃; More preferably, |T pm -T m |≤4.8℃; particularly preferably, |T pm -T m ∣≤2.8℃; Preferably, |T pm -T m |≤1.8℃; further preferably, |T pm -T m |≤0.9℃|; More preferably, |T pm -T m |≤0.5℃; particularly preferably, |T pm -T m ∣≤0.2℃; Preferably, the mass ratio of the core material to the wall material in the smoke-generating agent microcapsules is 1.6-3.8:1; Preferably, the coverage rate of the smoke-generating agent microcapsules is 65-90%.

3. The smoke generating agent microcapsule according to claim 1, characterized in that The melting point of the phase change material is ≥90°C; Preferably, the melting enthalpy ΔH of the phase change material m ≥130 J·g -1 ; Further preferably, ΔH m ≥160 J·g -1 ; Further preferably, ΔH m ≥180 J·g -1 ; Particularly preferably, ΔH m ≥210 J·g -1 ; Preferably, ΔH m ≥230 J·g -1 ; Further preferably, ΔH m ≥260 J·g -1 ; Further preferably, ΔH m ≥280 J·g -1 ; Particularly preferably, ΔH m ≥310 J·g -1 ; Preferably, the phase change material comprises a sugar alcohol, and the sugar alcohol is selected from at least one of sorbitol, mannitol, erythritol, maltitol, lactitol and xylitol; Preferably, the phase change material comprises a phase change material having a lower first melting point temperature T m1 The first sugar alcohol and the second sugar alcohol having a higher melting point temperature T m2 The second sugar alcohol, the peak temperature of the heating curve of the smoke-generating agent microcapsule T pm With T m1 、T m2 The relationship is T pm ∈[T m1 ,T m2 ]; Preferably, the smoke generating agent is selected from at least one of propylene glycol, ethylene glycol, glycerin, vanillin, vanillic acid, vanillyl acrylate, styrene, benzaldehyde, phenylpropanol, acetophenone, nicotine, nicotinic acid and amino acids, and more preferably glycerin; Preferably, the mass ratio of the smoke generating agent to the phase change material is 1:0.25-4.

4. The smoke generating agent microcapsule according to any one of claims 1 to 3, characterized in that: The wall material contains organosilicon-modified polyurethane, which is obtained by polymerization of silicon-containing polyurethane prepolymer and polyacrylate; Preferably, the polyacrylate is selected from at least one of polyethyl methacrylate, polyethyl methacrylate derivatives, polymethyl methacrylate and polymethyl methacrylate derivatives; Preferably, the weight average molecular weight of the polyacrylate is 200-10000; Preferably, the polymerization reaction is carried out in the presence of an initiator; Preferably, the initiator is selected from at least one of peroxides, sulfur-containing compounds, nitrites and lead compounds.

5. The smoke-generating agent microcapsule according to claim 4, characterized in that: The silicon-containing polyurethane prepolymer is obtained by mixing silicone, diisocyanate and hydroxyethyl acrylate; Preferably, the organosilicon is selected from at least one of dimethyl silicone oil, hydroxy silicone oil, silane, silicone, polysiloxane, long-chain alkyl silicone oil, amino silicone oil and amide silicone oil; Preferably, the weight average molecular weight of the organosilicon is 200-10000; Preferably, the diisocyanate is selected from at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate; Preferably, the mixing reaction is carried out in the presence of an organotin catalyst and an organic solvent; Preferably, the organotin catalyst is selected from at least one of dibutyltin dilaurate, dibutyltin diacetate and stannous octoate; Preferably, the organic solvent is selected from at least one of tetrahydrofuran, xylene and n-butyl acetate.

6. The smoke-generating agent microcapsule according to claim 5, characterized in that: The structure of the silicon-containing polyurethane prepolymer is shown in formula (I); Formula (I); Wherein, R1 is selected from C6-10 alkylene and C6-C14 arylene, and n is an integer greater than 3.

7. The smoke generating agent microcapsule according to any one of claims 1 to 3, characterized in that: The preparation method of the smoke-generating agent microcapsules is selected from at least one of a spray drying method, an emulsion polymerization method, a coacervation method, an in-situ polymerization method and a sol-gel method.

8. A heated cigarette, characterized in that: The heated cigarette comprises the smoking agent microcapsules according to any one of claims 1 to 7.

9. The heated cigarette according to claim 8, characterized in that: The heated cigarette comprises a smoke generating portion and a filter portion, and the smoke generating agent microcapsules are arranged in the smoke generating portion; Preferably, the mass loss rate of thermal decomposition of the smoke-generating agent microcapsules at a temperature not higher than 350° C. is ≥40%.

10. The heated cigarette according to claim 9, characterized in that: The heated cigarette further comprises cigarette paper wrapping the smoking portion, and the smoking agent microcapsules are arranged on the cigarette paper.

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